Recently, as data communication standards and the standardization of a terminal are carried out and devices become intelligent, a need to construct a more efficient and convenient system by associating a plurality of devices and services with each other is increased. A representative example that complies with such a need is a home network. A home network associates devices and services that are distributed at several places through wired or wireless communication.
In general, such a home network is based on Digital Living Network Alliance (DLNA). DLNA is a public cooperation organization for the commercialization of a home network. In DLNA, a compatible platform is constructed based on already constructed industry standards, for example, IP, HTTP, Universal Plug and Play (UPnP), and Wi-Fi. Companies that develop home appliances, wireless devices, and PC-related devices are introducing a guide line for product development based on DLAN industry standards related to a home network.
A home network may provide a content sharing environment in which digital content can be shared between devices or between heterogeneous services. For example, content stored in a specific device may be transmitted to another device, and the content may be played back through the device or content stored in a content server may be downloaded and played back by another device in response to a request from a specific device. For example, Korean Patent Application Publication No. 2009-0001973 and Korean Patent Application Publication No. 2010-0062799 describe technologies in which the domain of a plurality of devices operating in conjunction with each other over a network is configured and content may be shared between the devices within the domain.
Meanwhile, digital content is advantageous in that it may be freely distributed and obtained, but digital content may be easily exposed to an unlawful act, such as unapproved copy or spill, because it may be copied unlimitedly even without a loss of the data. Accordingly, in order to create a sound digital content use environment, content protection technology capable of safely protecting digital content from unlawful acts needs to be supported.
Digital Rights Management (DRM) is comprehensive digital content protection system for preventing the illegal copy and use of digital content and allowing only a user who has legal rights to use approved digital content. Such DRM adopts various element techniques, such as the safe distribution and spread of content, control of content use rights according to the policy, encoding, and decoding.
In order for content to be used legally and conveniently under a content sharing environment, DRM needs to be applied properly and compatible. To this end, an operating model capable of defining the entities and resources of a related system and generating and managing the defined system entities and resources needs to be able to be proposed. Furthermore, security means, procedures, and operating scenarios based on the defined system resources and the operating model need to be able to be proposed. Accordingly, there is an urgent need for the development of related technologies according to such a need.